A squid for skull surgery

Dr Paul Breedveld is developing a surgical tool that writhes around organs like a snake and then suddenly splits, turning itself into an octopus-like instrument deep inside the body.

Inspired by the arms of a squid Breedveld developed this surgical instrument that can bend in all directions. (Photo: Tomas van Dijk)

Imagine a surgeon cutting away a tumour in the pituitary gland, located under the brain, deep inside the skull. The surgeon has all the required equipment at hand, including a pair of grippers, a scalpel, camera and light. One can perhaps imagine a skull that has been opened and the brain parts pulled aside –which is normal practice - yet here the patient seems completely intact.

When the procedure is finished, the surgeon pulls all of the equipment out through a tiny hole in the sphenoid bone (the same hole through which the instruments were inserted), located at the base of the skull, from where the surgical tools continue on through the patient’s nose.

This is how biomechanical engineer, Dr Paul Breedveld, envisions the future of brain surgery; by manoeuvring a surgical instrument consisting of numerous, extremely flexible arms through the nostrils into the head. Last week he received a Vici grant from the Netherlands Organisation for Scientific Research worth 1.5 million euros to develop such a tool.

Breedveld is inspired by the arms of squid and octopuses. Lacking hard skeletal support, the tentacles of these animals are composed of muscular hydrostats, which are ingenious compositions of interacting muscles arranged in layers, bundles and volumes. By selectively tensioning and releasing fibres, tentacles can be manoeuvred with adjustable stiffness in a remarkable variety of poses.

With the squid tentacles in mind, the researcher developed an instrument in 2004 comprising of a ring of steel cables, surrounded by coil springs, which can bend in all directions. He now aims to elaborate on this invention, making it multi-armed and thinner.

“The instrument you see here is hollow,” says Breedveld, while holding his patented surgical instrument in his hand. It allows for the electrical cables needed for a camera at the tip to run through the instrument, he explains. “What I want to do now is to manoeuvre the instrument not with a separate set of steel cables, but rather with the electrical cables themselves, making them multi-functional so that the instrument no longer needs to be hollow and can thus be thinner.”

“I also want to devise smart ways to allow surgeons to efficiently steer all the arms,” he adds. “Basically I want to copy an entire squid.”